Conventional electrical AC power cable transmission may be limited in distance due to the properties of the cable. The maximum AC transmission distance at 50/60 Hz may be between 100 km and 200 km. Currently, for longer distance transmission, DC transmission is used instead.
In subsea power applications, distances may be greater than 200 km. In arctic areas, hydrocarbon reservoirs with step-outs up to 600 km from shore may be explored. AC power may be used for powering consumers at a subsea exploration site (e.g., pumps, compressors, motors etc.). Therefore, in a conventional system, the DC power transmitted to the sea ground may be converted into AC power in order to power the consumers at the subsea exploration site. However, the conversion of DC power to AC power may involve large and heavy equipment that complicates set-up of the exploration site and also increases the costs of the system. When designing a subsea power grid, reliability may be a factor. To increase reliability of a subsea power grid, the complexity of the power grid may be limited. In addition, the number of components with low reliability (e.g., non-redundant types of components) may also be limited. At present, only medium voltage distribution technology for AC solution may be reliable. Consequently, DC power may be converted to AC power subsea for subsea DC transmission systems. The DC-to-AC converting system may be complex and use a large amount of components, thus reducing of the system as compared to a subsea AC transmission system.